Flexible wire like Tigertail?
There are a few options that are worth considering.
The easiest is getting something called a crimp cover. It is basically a larger hollow crimp that fits over the functional squished crimp to make the whole thing look like a round bead. They are a bit more specialty than crimps so you might need to look in a jewellery-specific shop.
Another option is to use crimping pliers. These are single-purpose pliers that flatten and then fold the crimp bead, making it look rounder. There are some people who find this works, others say it weakens the crimp too much. It likely depends on the quality of the crimp and pliers.
There are also many types of crimps, as well as different lengths and diameters. Getting one that is only just large enough helps avoid the giant flat crimp look
I usually disguise the crimps by making sure they are not the last thing I thread on. Most times people thread their necklace and then a crimp, loop the wire through the finding, back through the crimp, and then squish and cut. That can look really messy. What I find is better is to use one or more crimps and thread beads in between them, like so:
Does that make sense? So you thread bead > crimp > bead > crimp > bead > clasp > turn around and thread back > crimp > cut wire one or two beads down from the last crimp.
The problem with this method is that you are usually working with small-hole beads that are strung tightly together, so it doesn't always work, but it is a nice easy finish that doesn't require any different supplies or tools
It is also handy if your piece is particularly heavy or if you don't trust your crimps to hold
Hope that helps